An unmanned underwater vehicle (UUV) may be used in a variety of applications, such as mapping the ocean floor or training a submarine crew.
FIG. 1 shows a UUV 10, which is disposed in a body of water 12 and which is attached to a ship 14 with a tether 16. The UUV 10 receives control signals (e.g., electrical or optical signals) from the ship 14 and sends data signals to the ship via a cable that runs inside of, or that is intertwined with, the tether 16. The control signals may command the UUV 10 to perform actions such as diving, surfacing, moving at a predetermined depth, illuminating an object (not shown in FIG. 1), grabbing the object, and generating a “ping” that simulates the reflection of a sonar signal from the hull of a submarine. And the data signals may include, e.g., pixels of an image captured by the UUV 10.
Unfortunately, the cost of the tether 16 may be prohibitive, and the space occupied by the tether and its storage assembly (not shown in FIG. 1) on the ship 14 may be significant. For example, if the UUV 10 is used to explore the ocean floor, then the tether 16 may be anywhere from one mile long to over five miles long. A tether of such length may be expensive to purchase and to maintain, and the tether storage assembly (not shown in FIG. 1), which includes the drum about which the tether is wound and the motor for rotating the drum and a boom for directing the tether over the bow of the ship 14, may be relatively large.
Furthermore, the need for the tether 16 may limit the applications for which the UUV 10 is suited. For example, the need for the tether 16 may prevent one on an airplane or helicopter from operating the UUV 10. Or, the presence of the tether 16 may limit the speed at which the ship 14 may sail and the distance that the ship may sail while the UUV 10 is deployed.